The Core will execute tasks of common interest for all subprojects, such as maintain lymphoblastoid cell lines (LCLs), obtaining new LCLs, and generating DNA from LCLs for distribution to the subprojects. The Core will also ensure the presence of a complete duplicate of CEPH cell lines that HGDP donates and maintain in Paris for generation of DNA and distribution to research workers. The Core will duplicate the database of CEPH and carry out preliminary database analyses, which will be distributed to research workers. The Core will duplicate the database of CEPH and carry out preliminary database analyses, which will be distributed to research workers. These analyses will be complementary to those to be executed at CEPH, and be distributed by CEPH to participants in their effort together with the results of analyses done in Paris. The Core will assure the communication and cooperation generate and discuss new hypotheses, methods, test, and computer programs, which can improve the quality of experiments and analyses.